1 files changed, 72 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c
new file mode 100644
index 0000000..2a32912
--- /dev/null
+++ b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c
@@ -0,0 +1,72 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+
+/* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b
+ *
+ * All curves taken from NIST recommendation paper of July 1999
+ * Available at http://csrc.nist.gov/cryptval/dss.htm
+ */
+#include "tomcrypt.h"
+
+/**
+  @file ecc_ansi_x963_export.c
+  ECC Crypto, Tom St Denis
+*/  
+
+#ifdef MECC
+
+/** ECC X9.63 (Sec. 4.3.6) uncompressed export
+  @param key     Key to export
+  @param out     [out] destination of export
+  @param outlen  [in/out]  Length of destination and final output size
+  Return CRYPT_OK on success
+*/
+int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen)
+{
+   unsigned char buf[ECC_BUF_SIZE];
+   unsigned long numlen;
+
+   LTC_ARGCHK(key    != NULL);
+   LTC_ARGCHK(out    != NULL);
+   LTC_ARGCHK(outlen != NULL);
+
+   if (ltc_ecc_is_valid_idx(key->idx) == 0) {
+      return CRYPT_INVALID_ARG;
+   }
+   numlen = key->dp->size;
+
+   if (*outlen < (1 + 2*numlen)) {
+      *outlen = 1 + 2*numlen;
+      return CRYPT_BUFFER_OVERFLOW;
+   }
+
+   /* store byte 0x04 */
+   out[0] = 0x04;
+
+   /* pad and store x */
+   zeromem(buf, sizeof(buf));
+   mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - mp_unsigned_bin_size(key->pubkey.x)));
+   XMEMCPY(out+1, buf, numlen);
+
+   /* pad and store y */
+   zeromem(buf, sizeof(buf));
+   mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - mp_unsigned_bin_size(key->pubkey.y)));
+   XMEMCPY(out+1+numlen, buf, numlen);
+
+   *outlen = 1 + 2*numlen;
+   return CRYPT_OK;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c,v $ */
+/* $Revision: 1.4 $ */
+/* $Date: 2006/12/04 02:50:11 $ */